Many scientists have spent many years attempting to find a carbon neutral or green fuel to use instead of gasoline. Some of the options that have been suggested over the years are simply not commercially viable as an alternative to gasoline, or are too expensive to be widely used, although biofuel and electric batteries have shown some promise. However, a fuel manufactured from water and carbon dioxide, by the car company Audi, has caused quite a stir and has turned the spotlight on the problem once again.
An innovative yet extremely simple laboratory technique was used to create the fuel, with the cooperation of the German company Sunfire. The first step was to use solar, wind, hydropower or another renewable energy source to heat water to temperatures of over 800 degrees C. Electrolysis was then used to decompose the steam into oxygen and hydrogen, and the carbon dioxide into carbon monoxide. Extreme pressure and temperatures were then used on the carbon monoxide and hydrogen to produce hydrocarbons, with the help of a reactor. Audi calls the resulting liquid blue crude, and e-diesel was produced by refining it in much the same way as standard crude oil.
E-diesel has an extremely low carbon footprint, according to the manufacturers, meaning that the amount of carbon consumed is the same as the amount created, a big contrast to regular diesel gas which when burned, adds just over 22 pounds of CO2. When e-diesel is manufactured, it absorbs some of the CO2 it needs from its surroundings, helping to reduce the greenhouse effect.
The Sunfire plant in Dresden, Germany is currently producing just 42 gallons of e-diesel each day, and that is one of the drawbacks to the carbon neutral fuel – it is very hard to scale. The British company, Air Fuel Synthesis experienced the same problem when they came up with a similar product in 2012.
However, Sunfire has announced plans to work together with car company Audi to build a larger plant capable of producing larger quantities of e-diesel, in an effort to get around the problem of scaling. Critics point out that e-diesel will still need a large amount of energy to be generated simply to create it. Once it is being manufactured on a larger scale, e-diesel will likely sell at between $1.14 and 1.70, or between 1 and 1.5 Euros per liter. Wind and solar technology is still relatively unsophisticated, meaning that most experts just don’t think these technologies will be able to satisfy the demand.
The introduction of e-diesel can only be a positive thing when it comes to making carbon neutral fuel, and other similar solutions will no doubt follow. Germany’s Minister of research and Education, Johanna Wanka, pointed out that an important contribution to protecting the climate can be realized if CO2 is widely used as a raw material. Wanka went on to say that the beginnings of a so- called green economy might be a reality once e-diesel is widely used.